An In-Depth Examination of Surgeon-Scientists’ NIH-Funded Areas of Research

Background: Few studies have examined which National Institutes of Health (NIH) Institutes or Centers (ICs) provide most of the funding to surgeons, nor examined the specifics of their research focus areas. A better understanding of both the goals of ICs and research focus areas for surgeons may facilitate further alignment of the two. Methods: A previously created database of NIH-funded surgeons was queried. To understand trends in funding, total grant cost was calculated for each IC in 2010 and 2020, and distribution of IC funds to each principal investigator (PI) category (surgeons, other physicians, and PhDs without a medical degree) was compared. Finally, total cost for Research Condition and Disease Categorization (RCDC) areas funded to surgeons compared to all of NIH was calculated. Statistical analyses were performed; a two-tailed p value of < 0.05 was considered significant. Results: The National Cancer Institute (NCI) awarded the largest percentage of all 2020 surgeon funding, 34.3% ($298.9M). Compared to the other ICs, surgeons held the largest percentage of the National Eye Institute’s (NEI) total funding in 2010 and 2020 at 8.7% and 9.0%, respectively. The RCDC super category comprising the most funding for surgeons was health disparities with 14.5% of all surgeon funding, followed by neurology (13.8%) and cancer (11.4%). Surgeons were awarded 10.8% of NIH’s transplant-related research, 7.0% of ophthalmology-related research, and 3.4% of cancer-related research in 2020. Conclusions: Our study shows surgeons have positioned themselves to examine new and myriad research topics while maintaining a focus on health disparities and cancer-related research.


Introduction
The status of surgeons funded by the National Institutes of Health (NIH) has been reported upon over the last decade through a myriad of studies. Our recent study identified NIH grants awarded to surgeons, non-surgeon physicians, and PhDs without a medical degree in June of 2010 and compared workforce and surgeon-lead grant specifics, such as total costs and research type (basic science, clinical outcomes, or clinical trial), to June of 2020. We found that 1) the number of surgeon-scientists funded by the NIH has significantly increased from 2010 to 2020 compared to both non-surgeon physician-scientists and the surgeon workforce and, 2) surgeons have maintained a significant portion of their portfolio, more than 70%, in basic science research [1]. However, current literature has not examined either which NIH Institutes or Centers (ICs) provide the majority of NIH funding to surgeons, or the specifics of their research focus areas. Relevant to this, each IC has its own strategic plan aimed at aligning the mission and goals of the institute or center with its scientific priorities [2]. Therefore, a better understanding of both the goals of ICs and research focus areas for surgeons may facilitate further alignment of the two [3]. By way of example, a recent study by Dowd et al. found that the National Institute of General Medical Science (NIGMS) provided the largest funding to trauma research. The authors concluded that an established and well-funded institute offers more resources that could be utilized by PIs pursuing trauma research compared to starting a new, smaller institute solely focused in this area [4]. Furthermore, implemented in 2008 at the request of Congress to address a more transparent method of reporting the relationship between NIH's research portfolio and public health needs, Research Condition and Disease Categorization (RCDC) was created. The RCDC categories include 292 condition, disease, or research areas that are linked to NIH grants [5,6]. Several studies have utilized RCDC information to further understand specific research topics, such as data science funded by the National Heart, Lung, and Blood Institute (NHLBI), trauma research, and research advocacy for schizophrenia, [4,7,8] but no study has used RCDC terms to examine the research of a specific group of NIH grant holders, in this case, surgeons. In our study, we sought to identify which ICs fund surgeonscientists as well as which research areas surgeons focus on by utilizing RCDC categories. To accomplish this, we queried a previously created comprehensive database of NIH funding for surgeons [1]. Herein, we report on IC funding for surgeon-scientists, including total costs awarded to surgeons by each IC in June of 2010 compared to 2020. We also compare the overall proportion of IC funding awarded to surgeons, other physicians, and PhD principal investigators (PIs) in both years. Lastly, we report on RCDC super categories associated with grants held by surgeons in 2020 compared to all of NIH, as well as the distribution of R01 grant research type of each super category.

and 2020 Surgeon-scientist Databases
A previously created database [1] that included NIH-funded surgeons, other physicians (MD, MBBS, and/or DO), and PhDs without medical degrees, curated in the internal NIH data platform, iSearch Grants (NIH Office of Portfolio Analysis's next-generation portfolio analysis platform; v2.4) [9], was queried for this analysis. Surgeons were Demblowski et al. Page 2 identified by searching key terms within NIH biographical sketches and verified based upon credentials obtained from university or academic online profiles. Cardiothoracic, general (including all general surgery-derived subspecialties), neurological, obstetrics and gynecology, ophthalmic, orthopaedic, otolaryngology, plastic and reconstructive (including oral-maxillofacial), urological, and vascular surgeons were included in the database. R01 grants were categorized into one of three research types: basic science, clinical outcomes, or clinical trials, based on grant titles and specific aims. The following information was pulled from the database for all grants awarded to surgeons in June 2010 and June 2020: PI name and PI number, grant title, specific aims, activity code, RCDC, administrative IC, grant number, and total cost.

NIH Institutes and Centers Analysis
The administrative IC is responsible for awarding grants in compliance with its current budget and funding strategies [10]. Total cost and the total number of grants awarded to surgeons from each IC was calculated and compared 2010 vs. 2020. In addition, the number of PIs funded by each IC for both 2010 and 2020 were used to calculate cost per PI for each IC in both years. The proportion of awarded costs to the PI categories (surgeons, other physicians, and PhDs) from each IC was also calculated and compared 2010 vs. 2020.  [2]. Funding from each represented < 2.0% of the respective IC total 2020 costs awarded to surgeons.

Research Condition and Disease Categorization Analysis
RCDC terms linked to grants held by surgeons in June of 2020 were identified, and grants without an RCDC term were excluded from this analysis. Notably, grants are often associated with several RCDC terms that are not mutually exclusive. Therefore, a grant's total cost is reported alongside every RCDC term linked to the grant, making total costs associated with RCDC terms significantly more than the actual total NIH funds available. This process is used by NIH when reporting yearly RCDC totals for NIH [6]. Furthermore, only terms that were included in the estimates of funding for 2020 for both NIH and surgeons were included in this analysis, resulting in 196 of the 292 RCDC terms related to surgical research. Due to the political impetus behind the use of RCDC terms in combination with the funding overlap and variability in reported totals, these terms only indicate relative research focus areas [5,6]. We calculated total costs for each super category and compared surgeon costs to all of NIH as a percentage of total funds for 2020 [6]. We then determined the distribution of RCDC total costs associated with R01 grants within each super category stratified by research type: basic science, clinical outcomes, and clinical trials. The median percentage and range were calculated for each research type.

Statistical Analysis
Data were expressed as IC total costs and treated as units of millions of dollars. Stratification by assessment year and awardee category (surgeons vs. non-surgeon) was performed. Bivariate chi-squared analyses were performed using total costs. Then, z-tests of funding proportions were performed, using the proportion from 2010 as the null hypothesis. The data were analyzed in two stages. The first analysis evaluated total funding from each IC awarded to surgeons compared to non-surgeons for 2010 versus 2020. The second analysis evaluated each individual IC in terms of percentage of overall IC funding that was awarded to surgeons in 2010 versus 2020. Finally, the corresponding RCDC super categories for surgeon funding were also provided in a descriptive fashion, analyses were limited to the top ten IC funding bodies listed above. Statistical analyses were performed using JMP, Version 14.0.0 (SAS Institute, Cary, NC). A two-tailed p value of < 0.05 was considered significant.  Surgeons compared to entire IC's 2010 vs. 2020 funding-IC funding to surgeons was then compared to the total funding from each IC for that year. Compared to the other ICs, surgeons held the largest percentage of NEI's funding in both 2010 and 2020 at 8.7% and 9.0%, respectively ( Figure 2). NIDCD significantly increased its funding to surgeons from 4.4% of its 2010 total costs to 7.3% in 2020 (p<0.05). A significant increase in proportion of funding awarded to surgeons compared to all non-surgeons from 2010 to 2020 was also observed for NCI, from 3.2% to 5.5%, NINDS, 1.9% to 2.7%, and NHLBI, 1.5% to 2.0% (p<0.05). NIGMS significantly decreased its funding awarded to surgeons, from 2.2% in 2010 to 1.0% in 2020 (p<0.05). Lastly, the proportion of IC funding awarded to surgeons remained stable for the remaining ICs.

Research Conditions and Disease Categorization
The RCDC super category comprising the most funding awarded to surgeons only was health disparities, 14.5% of all surgeon funding, followed by neurology (13.8%) and cancer (11.4%) ( Six hundred and twenty-seven R01 grants with associated RCDC terms were awarded to surgeons in 2020. The median percentage for each of the 24 super categories' basic science grants was 71.8% of total costs, ranging from 49.8% to 85.3% (Table 3). The median percentage of clinical outcomes grants was 19.2% of total costs, ranging from 9.2% to 39.2%, and the median percentage of clinical trial grants was 8.7% of total costs, ranging from 0.0% to 16.1%. Musculoskeletal and psychology-related research awarded more than 80% of their funding to basic science, and only one category, fetal-related research, awarded less than 50% of its funding to basic science research.

Discussion
Our study aimed to better understand the NIH-funded research areas surgeon-scientists focus on by analyzing both IC distribution of funding to surgeons and surgeons' research topics. We found that from 2010 to 2020, NCI remained the largest funding IC for surgeons, with a significant 10-year increase in the proportion of overall funding awarded to surgeons. Additionally, NEI remained the IC awarding the largest percentage of its funding to surgeons from 2010 to 2020 (8.7% to 9.0%, respectively). By examining RCDC we also found that health disparities research comprised the majority of surgeons' research focus, followed by neurology-and cancer-related research. Unexpectedly we also found that basic science comprised about 50-85% of each research topic's total funding. Using NIH RePORTER, Smithson et. al. found NIGMS, NCI, NHLBI and NIDDK to be the ICs to most often fund surgical department applicants from 1998 to 2018 [12]. Similarly, Mesquita-Neto et. al.
found NCI, NHLBI, NIDDK, NIAID, and NIGMS to be the NIH ICs to most frequently fund new awards to surgical departments from 2008 to 2018 [13]. These results mirror our study's findings, namely, the top ten NIH ICs to fund surgeons in 2010 and 2020 were: NCI, NIDDK, NHLBI, NINDS, NEI, NICHD, NIAID, NIGMS, NIDCD, and NIAMS. However, our data differs from these prior studies in that iSearch Grants rather than NIH RePORTER was utilized to obtain the publicly available data [1]. Our study included all surgeons found within iSearch Grants after querying biographical sketches of the grant-holding PIs rather than depending on departmental filters in NIH RePORTER [1]. When filtering by department in NIH RePORTER, only those departments affiliated with US medical schools are captured, and organizations with different departmental structures are not included in the query. By way of example, institutions such as Massachusetts General Hospital are not included in the database when querying by department but, are included when searching by PI or grant number [3]. Furthermore, our study also includes a broad representation of grant types, including all grants actively awarded to surgeons in June of 2010 and June of 2020 as well as all surgical specialties. Other studies include, for example, new R-series grants [13] or R01 grants and career development awards only [12]. In order to examine surgeon research focus areas, we queried RCDC terms. It is important however to understand that this analysis has its limitations. For example, text data mining is used to match grants to research categories, resulting in only best estimates [6]. The method is susceptible to semantics, especially over time, such as the shift from the term 'health inequalities' to 'health disparities' [14]. Additionally, the categories are not all mutually exclusive, resulting in more than one hundred percent of all NIH funding, and therefore the number of surgeons and/or grants, to be included in the dataset [6]. Furthermore, multiple terms are associated with each grant, thereby increasing the broad representation of research focus areas rather than pinpointing a research focus area of a particular group, or in this case, surgical specialty.

Conclusions
Our study represents an in-depth look at which NIH ICs fund surgeons' research as well as their areas of research focus. Importantly, we show key ICs have either significantly increased the proportion of funding to surgeons or at a minimum, maintained the percentage over the last decade. As NIH's total funding grows, and therefore each IC total funding also increases, surgeons continue to successfully obtain funding. While surgeons' research spans a broad representation of focus areas, a clear alignment between, funding ICs, and/or research focus area was observed in our study. Despite literature suggesting surgeonscientists are threatened, our study shows surgeons have positioned themselves to be involved in new and myriad research topics while maintaining a focus on health disparities, neurology-and cancer-related research. Includes the top ten ICs comprising 90% of funding awarded to surgeons in 2020. A significant a increase in total awarded grant costs as a proportion of total surgeon funding was observed for NCI and NINDS (p<0.05). NEI and NIGMS funding significantly b decreased in proportion of total surgeon funding from 2010 to 2020 (p<0.05), even though total amount of funding remained stable. The number of grants funded by each IC are listed within the bars for both years. Includes the top ten ICs comprising 90% of funding awarded to surgeons in 2020. A significant a increase in proportion of total IC funding awarded to surgeons compared to all non-surgeons was observed for NCI, NHLBI, NINDS, and NIDCD (p<0.05). NIGMS funding awarded to surgeons significantly b decreased in proportion of total IC funding compared to all non-surgeons from 2010 to 2020 (p<0.05). n.b. Percentages are rounded to the nearest whole number.